Rhubarb Mascarpone Mousse

This was quite complicated and my kitchen looked like a bomb went off in it, but the end result was beautiful and delicious. The recipe can be found at epicurious.com.

To summarize, this is a flat cake, split in half horizontally, spread with jam, and placed into a larger spring-form pan. The spring-form pan is then filled with rhubarb mousse. Lastly, a glaze is poured over the top.

Cake:

1 cup all purpose flour
1 teaspoon baking powder
1/4 teaspoon salt
1/2 stick (4 tablespoons) unsalted butter, softened
1/2 cup sugar
1 large egg, at room temperature 30 minutes
1 teaspoon vanilla
1/3 cup whole  milk

Preheat oven to 350 degrees F. Butter 9-inch cake pan and line bottom with a round of parchment paper. Butter paper, then dust pan with flour, knocking out excess.

Sift together flour, baking powder, and salt into a bowl. Beat butter and sugar together at medium-high speed until  pale and fluffy, about 2 minutes. Beat in egg and vanilla until  fluffy and combined well, about 2 minutes. Reduce speed to low and add flour mixture and milk alternately in 3 batches, beginning and ending with flour. Mix until  batter is just combined. Do not overmix.

Spread batter evenly  in pan and bake until  cake begins to pull away from sides of pan and a wooden pick or skewer inserted in center comes out clean, 20 to 25 minutes (cake will still be pale in color, not golden brown).

Cool for 10 minutes in pan on a rack, then invert onto rack and reinvert to cool completely right side up.

Mousse:

2 pounds rhubarb, cut into 1-inch pieces (8 cups)
1 1/2 cups sugar, divided
1/2 cup water, divided
3 teaspoons unflavored gelatin (less than 2 packages)
1 cup (8 ounces) mascarpone (I read cream cheese may be substituted) 
3/4 cup chilled heavy cream
1 teaspoon vanilla

Combine rhubarb, 1 1/4 cups sugar, and 1/4 cup water in a large heavy saucepan and cook over medium-high heat, stirring occasionally, until  rhubarb releases enough juice to almost cover rhubarb, 5 to 8 minutes. Reduce heat  and simmer mixture, stirring occasionally, until rhubarb falls apart and is reduced to about 4 cups,  25 to 30 minutes. Remove  from heat. Pour mixture into a large fine-mesh sieve set over a bowl and collect 1 cup syrup and set aside. Transfer rhubarb pulp to another bowl.

Soften gelatin in remaining 1/4 cup water 1 minute, then stir into hot rhubarb pulp until  dissolved. Set bowl inside a larger bowl of ice water and stir rhubarb mixture until  cooled  to room temperature (do not let set on ice) OR you can let it cool by itself, just stirring frequently while you’re doing the next part.

Beat together mascarpone, heavy cream, and vanilla with remaining 1/4 cup sugar until  it just holds  stiff peaks.

Fold cooled  rhubarb mixture into mascarpone mixture.

Assembly:

1/2 cup strawberry, rhubarb, or strawberry-rhubarb jam
Glaze

Prepare a 10″ springform pan by inverting the bottom piece so that the cake slides off easily when you’re ready to serve (the lip will be facing down). Spray with non-stick spray or lightly oil the inside of the pan.

Cut the cake in half horizontally. Center the bottom half into the prepared springform pan. Spread with jam. Place the other half of the cake onto the top. Spoon the mousse into the pan, covering all and smoothing the top. Chill, uncovered, until the mousse is set, at least 2 hours.

Yes, mine broke.

Glaze:

1 1/2 teaspoons unflavored gelatin
3 tablespoons water
1 cup rhubarb syrup, saved from above

Sprinkle gelatin over water in a small  heavy saucepan to soften, 1 minute. Heat gelatin over low heat  until  it has dissolved. Remove  from heat  then stir in reserved rhubarb syrup.

Pour glaze over chilled mousse, tilting pan slightly to cover it completely in an even layer. Chill, uncovered, until  glaze is set, at least 1 hour.

To serve:  Let cake stand at room temperature 30 minutes to soften slightly. Wrap a kitchen towel dampened in hot water around the side of the pan for about 15 seconds. Run the tip of a thin  knife around the edge of the pan, then gently unlock and remove sides of spring-form pan.